The present invention relates to a process and device for collecting, storing and draining rainwater for subsequent use as well as for discharging excess quantities of rainwater above the amount desired to be collected. In conventional home roof drainage systems, rainwater flowing from roofs is collected by guttering and directed, usually, to a series of downspouts or drainpipes which direct flow to the ground, sewers or sometimes into barrels. The present invention comprises a device which can be installed directly onto downspouts after a section somewhere between the gutter and the discharge and has been removed. With the device in place, rainwater, which initially flows from the gutter down the upper part of the downspout or drain pipe connected to the device of the present invention, thereafter flows into a storage vessel located within the present invention from the bottom thereof. The vessel is provided with an openable and closeable drain to allow water to be removed from that volume collected and water in excess of that predetermined volume is discharged directly to the sewer via an overflow from that storage vessel and the lower part of the downspout.
In known rainwater collection systems water is supplied to a vessel located at the end of a downspout or drain pipe that empties directly into the top part of that storage vessel. When the vessel is full further rainwater reaching it flows, via an overflow, practically directly to the sewer.
A disadvantage of these known systems is that once water has been collected it sometimes remains in the collection vessel for long periods of time and is not automatically replaced by fresh water the next time rain fall is collected. As a result, the quality of the stored water deteriorates. The quality deteriorates even further due to the fact that as rainwater is collected in an empty or partly filled vessel, the first water collected is the most contaminated with dirt, for instance originating from the roof, while the less contaminated water that follows is discharged off the top of the vessel to the sewer.
The present invention provides a process and device for collecting, storing and draining rainwater without these disadvantages. The rainwater can still be collected via a downpipe with the flow being directed into a storage vessel provided with a drain while excess water is discharged to the sewer via an overflow. This is achieved by introducing rain water into the vessel from a point near the bottom and causing water to flow through the vessel from bottom to top with excess water overflowing from near the top so that during collection periods water flows through the vessel continuously.
A downpipe is here understood to mean a pipe in which the water moves by gravity and for installation of the present invention has been cut and a segment removed. A through pipe is here meant to be a downpipe possessing a discharge possibility apart from the vessel.
A device with a through-pipe is known from Dutch patent application No. 7,711,556, but the process carried out in that device leads to the same disadvantages described above, since the contents of the vessel cannot flow through via the line indicated by 10.